I've been happy with Heroku, Dotcloud, and Webfaction. Of the three, Webfaction's the only one that's Python-specific (although not really), but both Heroku and

I've been happy with Heroku, Dotcloud, and Webfaction. Of the three, Webfaction's the only one that's Python-specific (although not really), but both Heroku and Dotcloud have Pythonistas on staff and take Python support really seriously.